Cap-tightening mechanism for collapsible tubes



July 18, 1939. G, w, TEMPLE 2,166,382

CAP-TIGHTENING MECHANISM FOR COLLAPSIBLE TUBES Filed Aug. 16, 1938 INVENTOR Gegge W Empia Patented July 18, 1939 UNITED STATES CAP-TIGHTENING MECHANISM FOR COL- LAPSIBLE TUBES George W. Temple, New York, N. Y., assignor to Victor Metal Products Corporation, Brooklyn, N. Y., a corporation of New York Application August 16, 1938, Serial No. 225,136

7 Claims.

This invention relates to mechanism for tightening to the limit, the caps of capped collapsible tubes.

Collapsible tubes are customarily supplied by the manufacturer thereof to users with caps screwed on to the neck ends of the tubes and the other ends of the tubes open, so that the tubes may be filled with their contents and then closed at the filling ends thereof on a suitable machine.

In handling and transit, however, it frequently happens that the caps become unscrewed to a greater or lesser extent and work their way off the necks so that they are not sufficiently tight and to not form adequate seals for the discharge ends of the tubes. Means have therefore been provided heretofore in connection with the filling machine which fills the open ends of the tubes, for tightening the caps on the tube necks by rotational operation. Said means, however, depends on the frictional engagement of the cap with a rotatable friction member. The friction member, regardless of the material of which it is made, wears out so rapidly that frequent replace ment thereof is required, and since access thereto is difficult, much time is lost and labor consumed in the replacement.

My invention therefore contemplates the provision of means for adequately engaging the tube cap and for rotationally tightening the cap on the tube, which means is durable, efficient in its operation and practically indestructible, not requiring replacement over long periods of time and long use.

My invention further contemplates the provision of a readily accessible and replaceable yieldable metallic member for engaging the cap and of means for rotating said member until the cap is tightened whereafter the cap and the member rotate freely to avoid injury to the cap or to the mechanism for tightening the cap.

My invention further contemplates the provision of a metallic spring operating in a hardened raceway, said spring being of the proper diameter to engage a cap and on the rotation of the spring to tighten the cap, and its raceway being of such nature that it adequately holds the spring in place without other aid and repair or replacement of the spring is practically unnecessary.

The various objects of the invention will be clear from the description which follows and from the drawing, in which:

Fig. 1 is a vertical section of my improved cap-tightening mechanism.

Fig. 2 is a side elevation of the same showing a multiplicity of the devices used in connection with a suitable filling machine.

Fig. 3 is a horizontal section of the cap holding spring and its raceway taken on the line 33 of Fig. 1.

Fig. 4 is a fragmentary enlarged horizontal section of the cap-engaging and tightening spring and its raceway, showing particularly the means for connecting and holding the end coils of the spring together.

In the practical embodiment of my invention which I have shown by way of example, the member I constitutes a fixed tube support such as is used, for example, in tube-filling machines. A plurality of tube-receiving openings I l are made in said member for the reception of a number of tubes [2, so that a number of tubes may be simultaneously filled and have the caps i3 thereof simultaneously tightened. The openings H are each suitably shaped to have the tubes rest therein, means being provided for preventing the rotation of the tubes within the openings. Said means being substantially identical for all the openings and the cap-tightening mechanisms be ing also identical to each other, a description of one will sufiice for all.

A leaf spring I4 is arranged in an enlarged part l5 of the opening II and is urged by a suitable adjusting screw l6, controlled by a. lock nut Ii, in the proper direction to engage and hold the tube I2 without injury thereto and to prevent rotation thereof during the cap-tightening operation. As shown, the tubes l2 are inserted into the openings II with the caps l3 thereof lowermost and with the open ends thereof uppermost so that the tube contents, usually in paste form, may be inserted into the tube through the open end and said open end thereafter closed.

The means for tightening the caps l3 comprises the spring-holding or cup member is having the central cap-receiving recess l9 therein extending downwardly from the upper face thereof and having the annular raceway 20 arranged outwardly of and around the upper part of said recess. The wall of the raceway 20 is hardened and preferably ground and polished to minimize the friction between said wall and the cap-engaging annular coil spring 2i, when the wall rotates relatively to the spring. Said wall is of arcuate cross-section to closely fit and to directly contact with said spring, its arc subtending an angle greater than 180 and preferably less than 270. The raceway engages part of the outermost and under surfaces of the spring and constitutes the sole means for retaining the spring in place in the cup member.

The cup member I8 is further provided with a central longitudinally extending opening 22 therethrough, which receives the shank 23 of the stop plug 24. Said plug has an enlarged head provided with an upper surface 25 shaped to fit and engage a substantial area of the lowermost surface of the cap, as will be best seen from Fig. 1. The plug 24 is readily removable from the cup member, being rather tightly but removably fitted into the opening 22 and into the enlarged upper end 26 of said opening. It will be understood that for caps having outermost surfaces of different shapes, different plugs as 24 having correspondingly shaped upper surfaces 25 may be inserted'into the cup member l8 to suitably engage said differently shaped outermost faces of the caps without injury thereto or mutilation thereof, the plug acting as a positioning and stop member for the cap and limiting the upward movement of the cup member.

For supporting and vertically reciprocating the cup member |8, the sleeve 2'! is provided, said sleeve being internally threaded as at 28 and engaging corresponding threads on the extension 29 of the cup member. Said sleeve 21 is normally urged upwardly by the spring 3|] interposed between the shoulder 3| of the sleeve and the collar 32 fixed to an intermediate point of the Vertically reciprocating rod 33. At its upper end, said rod is provided with a head 34 adapted to reciprocate in the interior opening 35 of the sleeve, which opening is provided with a shoulder 36 to limit the lowermost position of the rod 33 relatively to the sleeve. At its lower end said rod is provided with a suitable cam follower as 31 engaging the cam 38 on the shaft 39, the cam follower being suitably urged into engagement with its cam as by means of the spring 45 interposed between a suitable friction collar 4| at the lower end of the rod, and the gear frame 42.

For rotating the rod 33, a suitable worm wheel 43 is secured to the rod and engages the worm 44 on the drive shaft 45. Said drive shaft is rotated by any suitable rotating part of the filling machine, not necessary to be shown, to rotate the worm wheel 43 and therethrough to rotate the rod 33. Rotation of the rod 33 imparts rotation to the spring 3|] and the sleeve 21 owing to the frictional engagement of said spring with the collar 32 and the shoulder 3| of said sleeve.

It will be understood that a comparatively few revolutions or sometimes only part of the revolution merely is necessary to tighten the cap adequately on to its tube and therefore the rotation imparted to the sleeve by the spring 30 is suificient to permit the mechanism to accomplish its purpose even though the connection is not a positive one. It will further be understood that, if desired, the rod 33 may be keyed to the sleeve 2'! in the same manner as it is keyed to the worm wheel 43 though I prefer to effect rotation through the spring 3 for the reason that even a non-positive rotation given to the cup member i8 is sufiicient to insure the required rotation of the spring 2|, besides insuring a slipping action on excessive stress applied to the parts as when the cap I3 has been already tightly screwed into place.

The spring 2| is preferably formed of wire circular in cross-section and is of metal hard enough to wear almost indefinitely so that it need seldom, if ever, be replaced. If replacement should become necessary, such replacement is comparatively easy since the spring may easily be removed from the raceway 20 and a new spring substituted therefor, though normally it is adequately self-held in its raceway. Said spring is wound comparatively tightly, that is, there is a slight space between adjacent coils thereof to permit yielding of the spring when a cap is forced thereinto. This will be seen best from Fig. 3 wherein a hexagonal cap is shown in the position wherein it is gripped and held by the spring. The corners 50 of said cap displace two adjacent coils and fit into the space between them, causing the spring to grip the cap firmly and causing the cap to rotate with the cup l8 and the spring 2| in the proper direction and at the proper time until it is screwed home.

The displacement of the spring coils illustrated in Fig. 3, while slightly exaggerated, indicates how the cap, if it has a polygonal lateral surface, is firmly held by the spring. After the cap has reached its final tightened position and cannot be screwed any further on to the tube, the spring nevertheless retains its grip on the cap and since the cap can no longer rotate the spring also cannot rotate any further in spite of the rotation of the cup Hi. The spring therefore remains fixed in the raceway 20 while the raceway and the cup member rotate around the spring with the raceway maintained in contact with the spring. Owing to the hardness of the spring and of the wall of the raceway, very little, if any, wear occurs on the relative rotation of these parts so that the spring lasts almost indefinitely. It will be noted that the spring is in direct contact with the wall of the raceway, and that owing to the arcuate form of the raceway which extends upwardly past the horizontal center line of the spring and owing to the tendency of the spring to expand, it is self-retained in the raceway without the need for any retaining means whatever.

As shown in Figs. 3 and 4, the spring may be formed from a comparatively long length of suitably coiled wire, the coiled length being preferably wound on a mandrel of substantially the same diameter as the required interior diameter of the annular spring 2|. A piece, of the proper length to fit into the raceway, is then cut from the long length and the ends of the spring thus cut off are secured together in any suitable manner. As illustrated, particularly in Figs. 3 and 4, I prefer to use the spring coupling to secure the spring end coils 52 and 53 together. Said coupling comprises the narrow cylindrical central portion 54 of the diameter of the spring coils and the tapered portions 55, 56, said tapered portions being of sufficient outermost diameter to adequately enter into and engage the end coils 52 and 53 of the spring and to hold them together before said spring is inserted into its raceway. It will be understood that, if desired. the coupling 5| may be omitted, since after the spring is inserted into its raceway, it is selfretained in position.

The operation of my improved mechanism is as follows: The screw l6 and nut I"! are adjusted so as to exert the proper pressure upon the tube I2 through the spring l4 and to properly hold the tube l2 inserted into the opening against rotation. It being assumed that the rod 33 is moved to rest on the innermost point of the cam 38, being so moved by the spring 45 from the position shown in Fig. 1 and into the position shown in Fig. 2, the head 34 of the rod is in a position wherein it is retracted into engagement with the shoulder 36 of the sleeve 21. The cup l8 and its spring 2| are thereby lowered out of contact with the cap H3. In this position of the parts, the spring 3!] is expanded and does not exert sufficient upward pressure on the sleeve 21 to raise the spring 2| into engagement with the cap (Fig. 2). When, however, the shaft 39 rotates to carry the high point of the cam 38 against the cam follower 31, then the rod 33 moves upwardly into the position shown in Fig. 1 against the action of the spring 40 and compresses the spring 30 sufficiently to cause said spring to raise the sleeve 21, the cup member l8 and the spring 2|. Said spring 2| thereby engages at least part of the lateral peripheral surface 51 of the cap, whether said surface.- be of hexagonal, circular or of any other outline, it being understood that the innermost diameter of said annular spring 2| is slightly less than the greatest diameter of said surface 51. The spring is thereupon slightly compressed, or its coils slightly displaced, depending on the shape of the cap, but in any case the spring frictionally but firmly grips the cap to prevent relative rotation therebetween. In this position of the parts, the top surface 25 of the plug 24 engages the under or outermost surface of the cap and thereby determines the relative positions of the cap and spring, the middle of said surface 51 being preferably in horizontal alignment with the horizontal middle part of the spring.

In the position of the parts shown in Fig. l, as the shaft 45 continues to rotate, the cup member l8 together with its spring 2| are rotated thereby rotating the cap and screwing it firmly into place if it has not already been so screwed. After the cap is screwed into place by one or more revolutions of the cup member or a part of a revolution, the cup member nevertheless on its continued rotation rotates relatively to the spring 2| which remains fixed with the cap, so that no injury of the parts can occur, the spring at this time rotating in the raceway 20 as has been hereinbefore mentioned. On the continued rotation of the shaft 39, the rod 33 drops, releasing the pressure upon the spring 30 and permitting the sleeve 21 to drop aided by the engagement of the head 34 of the rod with the sleeve. The spring 2| is easily disengaged from the cap when said spring drops on the downward movement of the rod 33.

It will be seen that I have provided a simple but extremely durable mechanism not likely to be injured or to wear unduly, or to get out of order, but readily replaceable when necessary for tightening the caps of collapsible tubes while said tubes are inserted in a suitable filling machine, and that I have provided a device meeting the practical requirements hereinbefore referred to.

While I have shown and described certain specific embodiments of my invention, I do not wish to be understood as limiting myself thereto, but intend to claim the invention as broadly as may be permitted by the state of the prior art and the scope of the appended claims.

I claim:

1. In a machine of the character described, means for removably engaging a cap comprising a cup member having a central recess therein for the reception of a cap, an annular raceway surrounding the recess and having a wall arcuate in cross-section and sub-tending an angle between and 270, an annular coil spring engaging said raceway wall and projecting inwardly into the recess, the cup member having a central longitudinally extending opening therein, and a plug removably inserted in the opening and having a top surface shaped to frictionally engage a substantial area of the cap.

2. In a machine of the character described, a rotatable cup member provided with a raceway having a wall arcuate in cross-section and subtending an angle greater than 180 and less than 270, a coil spring in said raceway adapted to engage part of the lateral surface of a cap, and a removable central cap-engaging plug arranged centrally in the cup member below the raceway and adapted to engage a different surface of the cap.

3. In a machine of the character described, an annular coil spring, means within the spring and extending past the end coils thereof for connecting said coils, a cup member having an annular raceway provided with a wall in direct contact with the spring and constituting the sole means for maintaining the spring in the cup member, said wall extending inwardly past the outermost parts of the spring, and means for rotating and longitudinally reciprocating said cup member.

4. In a machine of the character described, means for holding a capped tube against rotation and with the cap thereof lowermost, means for engaging the lateral surface of the cap and rotating the cap in the cap-tightening direction, said cap-engaging means comprising a coiled annular spring having an innermost diameter less than the greatest diameter of the lateral surface of the cap, a tapered coupling inserted into the end coils of said spring and connecting said coils, and a raceway for the spring, said raceway having a wall in direct contact with the outermost part and with the lower part of the spring surface, and means for moving said spring into and out of engagement with said lateral surface and for rotating said raceway while said spring is in engagement with said surface, said spring remaining stationary and the raceway wall rotating thereabout when the cap has been rotated to its limit.

5. In a machine of the character described, cap-gripping means comprising an annular coil spring surrounding a central space therein and adapted to have the coils thereof displaced by a cap inserted into said space, said coils when displaced exerting inward pressure upon the lateral surface of said cap to hold the cap, a raceway for the spring having a wall arcuate in cross-section and in direct contact with the outermost and lowermost part of the spring, a member carried by the raceway and arranged to engage the under surface of the cap, and means for rotating said raceway to rotate the spring and to rotate the cap until rotation of the cap is halted whereafter said raceway rotates relatively to said spring while remaining in contact therewith.

6. In a machine of the character described, cap-gripping and rotating means comprising an annular spring, means fitted into the spring and extending past the end coils thereof to connect said end coils, and a rotatable raceway closely fitting the outermost and lowermost surfaces of said spring whereby rotation of the raceway normally rotates said spring until rotation of the spring is halted whereafter said raceway rotates relatively to the spring while remaining in contact therewith.

7. In a machine of the character described, cap-gripping and rotating means comprising an annular spring and a rotatable raceway closely fitting the outermost and lowermost surfaces of said spring and comprising the sole means for maintaining the spring in its operative position whereby rotation of the raceway normally rotates said spring until rotation of the spring is halted whereafter said raceway rotates relatively to the spring, and means carried by the raceway for engaging the under surface of a cap to position said cap relatively to the spring.

GEORGE W. TEMPLE. 

